Preliminary validation of a point‐of‐care ethylene glycol test for cats

Objective – To evaluate the sensitivity and specificity of a newly available, semi‐quantitative, cage‐side test for the detection of ethylene glycol (EG) toxicosis in cats. Design – Prospective, laboratory study. Setting – University teaching hospital. Animals – This study utilized samples from 57 cats, whose blood had been anticoagulated with EDTA and submitted to the hospital's laboratory for a complete blood count. Samples were centrifuged, and the plasma separated, aliquoted, and immediately frozen at ?30 °C. Interventions – Samples were randomly divided into 2 primary groups (Group 1: no EG added, Group 2: EG added). Twenty microliters of plasma from each of the Group 1 samples was applied directly to the test strip. Plasma samples from Group 2 had EG added at different concentrations to achieve approximate final concentrations of 20, 60, or 80 mg/dL. These samples were then applied to the test strip. Measurements – Two readers who were blinded to the sample preparation procedure and isolated from each other were asked to categorically interpret the colorimetric reaction on the randomly presented test strips. Main Results – The agreement of the 2 reviewers at the 3 different levels of EG concentrations (20, 60, 80 mg/dL) were 0.7, 0.7, and 0.5, respectively. Thus, the readers demonstrated substantial agreement while reading the 2 lower concentrations, while at 80 mg/dL the level of agreement was moderate. Overall, the sensitivity of the assay increased as the concentration of EG increased (reviewer 1: 67%, 67%, 86%; reviewer 2: 56%, 89%, 100%), while the specificity of the assay decreased with increasing concentrations of EG (reviewer 1: 77%, 45%, 50%; reviewer 2: 77%, 53%, 25%). Conclusions: Because of the likelihood for false negatives and false positives, results from this test must be viewed in light of clinical data and should not be relied upon as a lone diagnostic test.     

作物残体与其生物炭配施对土壤有机碳及其自身矿化率的提升

【目的】本研究通过探讨小麦和玉米残体与其生物炭配施对土壤各组分有机碳及其自身有机碳矿化的影响,揭示其在土壤固碳和培肥方面的效应,为农田有机物资源合理利用提供理论支撑。【方法】采用室内恒温培养试验,共设置小麦或玉米残体(根茬、秸秆)和秸秆制成的生物炭单施(WS、WR、WB、MS、MR、MB),配施(WS+WB、WR+WB、MS+MB、MR+MB)以及对照(CK)构成的11个处理,培养期间测定土壤CO2释放量,培养结束后测定土壤总有机碳(TOC)、可溶性有机碳(DOC)、微生物量碳(MBC)、颗粒有机碳(POC)以及粗细颗粒有机碳含量(CPOC、FPOC)。【结果】添加玉米有机物料对土壤TOC、MBC、POC、CPOC和FPOC含量的增加作用普遍高于添加小麦有机物料。添加小麦或玉米秸秆对土壤TOC、POC、CPOC、FPOC含量的增加作用均高于添加根茬。单独添加生物炭,作物残体与生物炭配施和单独添加作物残体处理分别在培养的第4、8、21 d有机碳矿化速率最大,为有机碳矿化快速期,之后矿化速率减缓并逐渐趋于稳定。单独添加作物残体其有机碳累积矿化率最大,达到30%~46%;与对照相比,添加有机物料的各处理均显著增加了土壤TOC含量,其中添加生物炭处理土壤TOC含量增幅最大;单独添加小麦和玉米生物炭处理,土壤TOC含量分别显著增加34.4%和36.5%,但其有机碳累积矿化率仅为3%左右,土壤FPOC含量及敏感性指数在单独添加生物炭处理最高;小麦和玉米残体与其生物炭配施处理,土壤MBC和CPOC含量分别显著增加80.2%~199.2%,且其有机碳累积矿化率为12%~19%,介于生物炭和残体单施之间,土壤CPOC含量及敏感性指数均表现为配施处理最高。【结论】单独添加作物残体能够较好地补充土壤养分,但CO2释放量显著高于单施生物炭及配施处理;单独添加生物炭其有机碳累积矿化率较低,短期内对土壤养分的补充作用较小。作物残体与其生物炭配施可以较好地克服各自单独施用的弊端,尤其是玉米秸秆与其生物炭配施,在保证作物养分供应的同时能增加土壤碳库储量,对土壤肥力提升效果更好。     

基于方程对等法的地基抗压刚度研究

【目的】研究影响动力基础竖向振动特性的关键参数——地基抗压刚度。【方法】采用方程对等法对弹性半空间理论进行简化,修正了地基抗压刚度的计算公式。【结果】得到了能较好地反映基础竖向振动、基底面积和基底压力等诸多因素影响的地基抗压刚度计算公式。【结论】归纳出有关地基抗压刚度的变化规律,为更准确地确定动力基础系统的动力参数提供了参考。     

小麦-玉米轮作体系中秸秆还田方式对土壤肥力及作物产量的影响

【目的】探讨小麦-玉米轮作体系下不同秸秆还田方式对土壤肥力和作物产量的影响,旨在为促进小麦-玉米连续轮作区的农业可持续发展提供理论依据。【方法】在陕西关中地区,于2008-2010年采用2年4季的田间定位试验,以玉米秸秆不还田-小麦秸秆不还田为对照（CK）,比较玉米秸秆覆盖还田-小麦秸秆高留茬还田（T₁）、玉米秸秆直接还田-小麦秸秆高留茬还田（T₂）、玉米秸秆直接还田-小麦秸秆直接还田（T₃）3种秸秆还田方式对土壤碳储量、养分含量及作物周年产量的影响。【结果】与CK相比,3种秸秆还田方式下耕层（0～20 cm）土壤总有机碳储量（C_T）、土壤活性有机碳储量（C_L）、土壤碳库管理指数（CMI）及土壤全磷、硝态氮、速效钾含量和作物周年产量均增加。3种秸秆还田方式对C_T、C_L及CMI的影响表现为T₃>T₂>T₁;对作物周年产量的影响则表现为T₂>T₃>T₁;对土壤养分的影响无明显规律性,但是对速效钾含量的影响表现为T₂>T₃>T₁。【结论】综合考虑,在陕西关中小麦-玉米轮作体系中,玉米秸秆直接还田-小麦秸秆高留茬还田模式（T₂）是较优的耕作方式。     

小麦粒位效应研究进展

从不同粒位对籽粒性状影响的研究和粒位效应形成的机理2个方面对小麦穗部不同粒住的粒位效应研究情况进行了综述，旨在为有效利用粒位效应提高小麦品种的选种效果、延长品种的利用寿命和深入研究提供科学依据。     

贵州省威宁草海主要野生鱼类重金属含量及健康风险评价

[目的]了解贵州省威宁草海鱼类重金属含量水平,并进行鱼类食用安全性评价,为威宁草海的鱼类水生生态环境保护和食用安全性提供参考依据.[方法]选择黄颡鱼、鲫鱼、鲤鱼和花鳅为研究对象,测定分析其肌肉和内脏中的8种重金属含量,运用Pearson分析鱼体中重金属含量与生长参数和水体理化因子的相关性,并运用单因子污染指数法、综合污染指数法和目标危险系数法进行污染评价.[结果]4种鱼体中的重金属含量排序为Zn>Cu>Cr>Pb>As>Ni>Cd>Hg,对重金属的累积整体上表现为鲫鱼>鲤鱼>花鳅>黄颡鱼,与国家标准GB 2762—2017《食品安全国家标准食品中污染物限量》比较,除Cu、Hg、Zn、Ni和As外,其余重金属均超标.鱼体各组织的重金属含量总体表现为内脏>肌肉.鲫鱼和鲤鱼的重金属含量随年龄的增加而上升,花鳅的重金属含量则随年龄的增加而降低.Pearson相关分析结果表明,Zn和Cd与体重、Cu与体长呈显著正相关(P<0.05,下同);Hg与硝酸盐氮(NO3-N)呈极显著正相关(P<0.01);Cr与总磷(TP)和NO3-N呈显著负相关;Cu与TP呈显著正相关.单因子污染指数表明,除Hg外,其余重金属在鱼体中有污染状况;综合污染指数表明,花鳅的肌肉处于轻度污染水平,鲫鱼和鲤鱼的内脏分别处于重度和中度污染水平.健康风险评价显示4种鱼的单一重金属危害系数(THQ)和复合重金属危害系数(TTHQ)在成人和儿童中均小于1,儿童的THQ和TTHQ均大于成人.[结论]威宁草海鱼体内存在重金属含量超标现象,重金属污染主要元素是As,食用黄颡鱼、鲤鱼、鲫鱼和花鳅虽然不会造成潜在健康风险,但相关部门对鱼类重金属的污染应给予管控.     

青贮玉米开发利用与栽培技术

青贮玉米在畜牧业发展中的重要地位是其它饲草、饲料作物代替不了的，其开发利用前景看好。青贮玉米正逐步走向农家、走向市场，其栽培技术较为关键。     

种植密度对春大麦物质积累与转运的影响

为给大麦高产优质栽培中种植密度的合理选择提供理论依据,以蒙啤3号、甘啤4号、蒙啤5号、垦啤7号4个品种为供试材料,分析了375万、450万、525万和600万株·hm^-24个种植密度下大麦干物质和氮素积累、转运的规律。结果表明,随着种植密度的提高,大麦干物质花前积累量呈先升后降趋势,积累率及对籽粒产量的贡献率呈先降后升趋势,茎叶的干物质转运量在525万株·hm^-2种植密度下最高。氮素花前积累量和转运量均呈先升后降趋势,花前积累率、转运效率及对籽粒氮素的贡献率呈先降后升趋势。不同种植密度下各大麦品种茎秆干物质转运量均大于叶片,转运效率则表现为叶片大于茎秆,干物质转运对籽粒产量的贡献率以茎秆较高。蒙啤3号和甘啤4号各器官氮素转运量以叶片较高,蒙啤5号和垦啤7号则以茎秆较高;转运效率均以叶片较高;蒙啤3号和甘啤4号氮素转运对籽粒氮素的贡献率以叶片较高,蒙啤5号和垦啤7号则以茎秆为高。在本试验条件下,大麦最高产量的种植密度范围为550万～558万株·hm^-2。     

膨胀颗粒饲料对奶牛生产性能、血液生化指标及营养物质表观消化率的影响

[目的]研究在奶牛中应用膨胀颗粒饲料对生产性能、血液生化指标及营养物质消化率的影响.[方法]试验选用42头中国荷斯坦奶牛进行为期30 d的饲养试验和为期7天的消化试验,[结果]表明膨胀颗粒饲料能显著提高血清中葡萄糖的含量(P＜0.05);显著降低乳中固形物率(P＜0.05).[结论]膨胀颗粒饲料对产奶量、饲料转化率和营养物质的表观消化率均有提高作用,虽差异不显著,但仍具有一定的经济效益.     

Embryonic and larval development of garpike from the Adriatic Sea

Although information about embryonic and larval development of garpike, Belone belone (Linnaeus, 1761), is present in the published literature, the bulk of research concerns garpike from the northeastern Atlantic Ocean and the Baltic Sea. The present work describes the embryonic and larval development of garpike, Belone belone, from the Adriatic Sea, and methods used for incubation of fertilized eggs in aquarium conditions. Because garpike is, as suggested by some authors, divided into subspecies, we conclude that some differences in embryonic development could also be expected. In the present study, eggs were fertilized using the dry fertilization method and were incubated in a tank equipped with aeration and constant sea water flow. Salinity and content of dissolved oxygen were constant, and the temperature varied between 19.4 and 22.3°C. Eggs were spherical, measuring 3071.9 ± 75.73 μm in diameter. Yolk sacs were homogeneous and did not contain oil globules. The first larvae hatched 329 h and 47 min after fertilization. Absorption of the yolk sac occurred 17 h – 48 h after hatching and the total length of newly hatched larvae was 9.78 mm. The peculiarities observed in the embryonic and early larval development are evidence of an exceptional plasticity and adaptive potential, which could be considered as helpful features in extending the natural range of occurrence of this species.